Products & Services
Tolerance Limits










1. ON THE CUTTING DIAMETER OF STANDARD REAMERS
The diameter is measured across the circular land immediately behind the bevel or taper lead. The toleranc is in accordance with DIN 1420 and is intended to produce H7 holes.

MILLIMETRES
Diameter
Tolerance Limit
Over
Up to and including
High
+
Low
+
3
0.008
0.004
3
6
0.010
0.005
6
10
0.012
0.006
10
18
0.015
0.008
18
30
0.017
0.009
30
50
0.021
0.012
50
80
0.029
0.016











2. ON A H7 HOLE

MILLIMETRES
Diameter
Tolerance Limit
Over
Up to and including
High
+
Low
+
3
0.010
0
3
6
0.012
0
6
10
0.015
0
10
18
0.018
0
18
30
0.021
0
30
50
0.025
0
50
80
0.030
0






















3. When it is necessary to define the dimensions of a special reamer intended to cut to a specific tolerance, e.g. D8, this well proven guide can be used.

Example of a 10mm hole with tolerance D8.

Maximum diameter of hole = 10.062
Minimum diameter of hole = 10.040
Hole tolerance (IT8) = 0.022

The maximum limit for the reamer is the maximum limit of the hole size reduced by 0.15 times the tolerance for the hole. The value is rounded up to the next higher multiple of 0.001mm

0.15 x hole tolerance (IT8) = 0.0033, rounded up = 0.004

The minimum limit for the reamer is the maximum limit of the reamer reduced by 0.35 times the tolerance for the hole. The value is rounded up to the next higher multiple of 0.001mm.

0.35 x hole tolerance (IT8) = 0.0077, rounded up = 0.008
Maximum limit for reamer = 10.062 - 0.004 = 10.058
Minimum limit for reamer = 10.058 - 0.008 = 10.050

A similar method can be used for other tolerances when required.

© Sandvik ABLatest update: 11/23/2006 01:36:18 PM

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